The core silica gel particles (Fractosil 500, 230-400 mesh) were washed
sequentially with dilute nitric acid, distilled water, and high purity
methanol and then dried in a vaccuum oven. These cleansed particles were
heated with aminophenyltrimethoxysilane in a mixture of isopropyl alcohol,
water, and acetic acid. This polymerizes a thick layer of aminophenyl silane
on the surface of the particles. These particles are treated with sodium
nitrite in sulfuric acid at 0-5 degrees to make the diazonium salt and this
is heated in sulfuric acid to decompose to the phenol. Now you have phenol
bonded particles.- Anal. biochem. 181,66-74 (1989) Let me know if you try it.
Dan Schindler LIDANIEL at WEIZMANN.WEIZMANN.AC.IL